This invention relates generally to an apparatus for providing security to a structure and, in particular, an impulse radar security system that allows for monitoring the interior and exterior of a residential or commercial structure.
Typical electronic security systems include a variety of sensors (i.e., photo, sound and/or motion detectors) that individually communicate with a central control unit. When suspicious or uncharacteristic events occur, sensors sense the event, transmit data to the central control unit, which processes the data and, based upon the defined parameters of the security system, activates an alarm to warn of the event. These types of security systems are quite costly and may require extensive modification to the structure during installation. Additionally, these systems provide minimal information to the user other than to warn of the event.
The present invention provides a security system that can provide a user with data on the directional movement, velocity and location of an object within and around the perimeter of a structure with the use of radio energy. The system comprises a sensor unit having at least one antenna for transmission of at least one signal into a defined area of the structure and receipt of at least one reflected signal. Any intrusion in the area is detected upon a change in the waveform received by the antenna. The received signal is transmitted from the sensor unit to a control unit, comprising, in part, a preprogrammed data processing unit that can determine the movement of the intruder. Utilization of a plurality of sensor units allows the user to obtain additional information on the velocity and location of the intruder. Additionally, as with conventional security systems, the system can provide an electrical signal to a display device to illustrate the intruder""s movement, velocity and location and to activate a sound and/or light device to attract the attention of the intruder and warn others of the intruder""s presence.
It is another object of the present invention to provide a security system that allows for rapid, efficient data processing by down-sampling the signal received by the antenna.
It is another object of the present invention to provide a security system that provides for time-variable range gain of the signal proportional to the average signal loss.
It is another object of the present invention to provide a background removal filter that specifically rejects stationary targets and identifies only targets which have changed position over a specified time interval.
It is another object of the present invention to provide a security system that compensates for the undesired gradual shift or change in the output signal over a period of time by incorporating a time-variable background removal filter.
It is another object of the present invention to provide a security system to track and identify a plurality of signals received by the antenna and selectively filter out undesired signals thereby allowing the user to focus on specific objects.
Examples of the more important feature of the invention thus have been summarized rather broadly in order that the detailed description thereof that follows may be better understood, and in order that the contributions to the art may be appreciated. There are, of course, additional features of the invention that will be described hereinafter which will form the subject of the claims appended hereto.